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When to plant Basil in Barnstable, MA

In Barnstable, plant Basil in spring between April 25 and May 16, once soil temps hold above 50°F. Barnstable's last frost averages April 18, so most warm-season crops establish quickly once soil holds above 60°F. For a fall crop, sow between and — roughly 50–75 days before the first frost on October 24.

When to Plant Basil in Barnstable, MA

Basil
Barnstable County, Massachusetts Zone 7a July

Barnstable County, Massachusetts gardeners: here's your July plan

July is a pivotal month for Barnstable County, Massachusetts gardens. Focus on these tasks first and you'll set up the rest of the season for success.

Avg. last frost April 18
Avg. first frost October 24
Soil temp (4") 86°F
Watering Low
Pest pressure High
Daylight 14.7 hrs
  1. Pick basil

    The more you pick, the more the plant produces. Letting fruit overripen tells the plant it's time to stop.

Before August arrives, get these ready
  • First harvests: basil

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Basil is a fragrant warm-season herb essential to Italian and Thai cuisines. It comes in many varieties including sweet, Thai, purple, and lemon types.

Barnstable, Massachusetts is in USDA Zone 7a. The average last spring frost is April 18 and the first fall frost is October 24, giving you a growing season of approximately 189 days.

At an elevation of 518 feet, Barnstable County receives approximately 45.5 inches of rainfall annually with predominantly silt loam soil. Summer highs average 91°F, providing good warmth for Basil during the growing season.

Barnstable, MA (Zone 7a) Moderate season
189 days
Last Spring Frost April 18
189 growing days
First Fall Frost October 24

Barnstable Soil Profile

Soil Type

Silt Loam

Soil pH

5-6.4

Drainage

Well Drained

Basil Planting Risk Windows

Early Start (70% safe) ✓ Fits season (57 days to spare)
Start indoors: Feb 20 Transplant: Apr 24 🍅 Harvest: Jun 19 – Aug 21
Recommended (50%) ✓ Fits season (56 days to spare)
Start indoors: Feb 28 Transplant: May 2 🍅 Harvest: Jun 27 – Aug 29
Safe Start (90%) ✓ Fits season (50 days to spare)
Start indoors: Mar 23 Transplant: May 25 🍅 Harvest: Jul 20 – Sep 21

Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.

Soil Compatibility in Barnstable

How your county's soil matches Basil's growing requirements.

Soil pH

Your soil pH (5.0–6.4) is more acidic than Basil prefers (6.0–7.0). Add garden lime to raise pH.

Soil Texture

The silt loam soil in Barnstable County is excellent for Basil — good drainage, moisture retention, and nutrient holding capacity.

Organic Matter

Organic matter is moderate (3.0%). Annual compost additions will help Basil.

How to Plant Basil

0.5"
Planting Depth
8"
Between Plants
12"
Between Rows

Succession Planting Basil

4
successive plantings in your 189-day season

Sow every 5.7 weeks. Last sowing by Aug 10 to harvest before frost.

Basil Water Budget

Plant needs
0.6″/week
Rainfall provides
1.0″/week
Watering frequency Natural rainfall sufficient
Season total 0 gal / 100 sq ft

Monthly Watering Guide for Basil

Basil needs approximately 0.6 inches of water per week (2.6" per month). Here's how your county's rainfall compares month by month.

Month Basil Needs Rainfall You Supplement Action
Jan 3.2" 0" ❄️ Dormant
Feb 3.1" 0" ❄️ Dormant
Mar 4.2" 0" ❄️ Dormant
Apr 2.6" 3.6" 0" ✅ Rainfall sufficient
May 2.6" 4.7" 0" ✅ Rainfall sufficient
Jun 2.6" 4.7" 0" ✅ Rainfall sufficient
Jul 2.6" 4.9" 0" ✅ Rainfall sufficient
Aug 2.6" 4.2" 0" ✅ Rainfall sufficient
Sep 2.6" 3.4" 0" ✅ Rainfall sufficient
Oct 2.6" 3.3" 0" ✅ Rainfall sufficient
Nov 3.2" 0" ❄️ Dormant
Dec 3" 0" ❄️ Dormant

Water needs are for active growing months only (Apr–Oct in Barnstable County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.

Basil Heat Requirements (GDD)

What are Growing Degree Days (GDD)?

Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.

Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.

Basil needs ~1,141 GDD — county provides 3,449 GDD Excellent fit

Basil Planting Timeline — Barnstable, MA

Basil Planting Calendar

Activity When Date Range
Start Indoors February 28 Feb 28 – Mar 14
Transplant Outdoors May 2 May 2 – May 16
Direct Sow April 25 Apr 25 – May 16
Harvest June 27 Jun 27 – Aug 29

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February Start Indoors
March Start Indoors
April Direct Sow
May Transplant Outdoors Direct Sow
June Harvest
July Harvest
August Harvest
September
October
November
December

Growing Conditions

☀️ Sun

Full Sun (6-8+ hours)

💧 Water

0.6"/week · Natural rainfall sufficient

📅 Days to Maturity

50–75 days

🧪 Soil pH

Needs 6–7 · Your soil: too_acidic

🗺️ USDA Zone

Zone 7a

📆 Growing Season

189 days in Barnstable County

Growing Tips for Basil in Barnstable

Direct sow Basil outdoors after April 18 in Barnstable County when soil has warmed and frost danger has passed.

General growing tips

Start seeds indoors or direct sow after last frost. Pinch flower buds to extend leaf production. Harvest leaves from the top down, cutting just above a leaf pair.

Companion Planting

Good Companions

Avoid Planting Near

  • Rue
  • Sage

Check more plant combinations with our Companion Planting Checker →

🌾 Save Your Own Basil Seeds
Life Cycle Annual
Pollination Self-Pollinating
How to Collect Let flower spikes dry brown on the plant.
Storage Store airtight; viable 5 years at 35°F, under 45% humidity.

Isolate 150 ft between varieties. Different basil species can cross.

When should I plant Basil in Barnstable, MA?

In Barnstable, MA, plant Basil after the last frost (around April 18) and before the first frost (around October 24). Best results when soil holds above 50°F.

What growing zone is Barnstable, MA for Basil?

Barnstable sits in USDA Zone 7a. Basil grows reliably in zones 4a through 11b, so it's a good fit here.

Can Basil grow in Barnstable's climate?

Yes — Basil grows well in Barnstable's temperate climate. Barnstable averages a 189-day frost-free season, with last frost around April 18 and first frost around October 24.

🌱

Your Barnstable County Garden Planner — Free

A 22-page printable planner built for Barnstable County (Zone 7a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Barnstable County, MA. Local conditions may vary. Last updated: July 2026.